Term
| 5 stages of neurodevelopment |
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Definition
NEURAL PLATE INDUCTION
NEURAL PROLIFERATION
MIGRATION & AGGREGATION
AXON GROWTH & SYNAPSE FORMATION
NEURON DEATH & SYNAPSE REARRANGEMENT |
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Term
| When is neural plate induced? Where is it located? |
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Definition
3 weeks post conception
Ectodermal tissue on dorsal surface of embryo
1ST MAJOR stage of neurodevelopment |
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Term
| What is the organizer layer of the embryo? |
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Definition
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Term
| TOTIPOTENT vs. MULTIPOTENT |
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Definition
TOTIPOTENT - stem cell can become ANY cell; before plate induction
MULTIPOTENT - stem cell can be either neural or glial stem cell; after plate induction |
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Term
| Two criteria for stem cells? |
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Definition
Need unlimited capacity for self-renewal
Ability to differentiate into different types of mature cells |
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Term
| What does the hollow neural tube become? |
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Definition
| Spinal canal & ventricles (continuous CSF filled tube) |
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Term
| 3 swellings at anterior end of neural tube? |
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Definition
| Forebrain (prosencephalon), mesencephalon, rhombencephalon |
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Term
| When does cellular proliferation begin? |
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Definition
When neural tube has fully formed
Occurs primarily in ventricular zone by precursor cells |
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Term
| Different stages of neural proliferation |
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Definition
| Symmetrical and asymmetrical (precursor cell turns into two cells; one stays in VZ other migrates out) |
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Term
| Different methods of neuronal migration? |
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Definition
Somal Translocation - can be either radial or tangential; extension grows from cell body to follow chemical signals
Glial Mediated - cell travels along radial glial fibres; only radial |
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Term
| Who proposed chemoaffinity hypothesis? |
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Definition
Sperry after frog experiments with the spinny eyes
States that postsynaptic targets release specific chemical labels which guide axon |
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Term
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Definition
| Cytoplasmic extension coming out from growth cone of neurite process (filopodia navigates through chemical environment to find proper path) |
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Term
| Why are topographic maps believed to have evolved? |
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Definition
To reduce volume of neural connections in brain
Grow based on topographic gradients - axons growing from one topographic location to another (retina to SC) are guided to terminals to be organized the same way on each |
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Term
| What glial cells are most important for synaptogenesis? |
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Definition
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Term
| What is the most prominent class of life sustaining chemicals? |
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Definition
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Term
| temporo-spatial pattern of synaptogenesis |
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Definition
Visual cortex - peak at 7-8 months; pruning reduces to adult levels by age 3
Frontal cortex - peak at 2 years; pruning reduces to adult levels by late adolescence |
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Term
| What is the pattern of dendritic branching? |
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Definition
| Follows organization of cortical layers - deep to superficial (inside out) |
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Term
| Progressive events in the brain vs. regressive? |
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Definition
Progressive - synaptogenesis, neurogenesis
Regressive - apoptosis, synaptic pruning |
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Term
| What brain region takes longest to reach maturity? |
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Definition
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Term
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Definition
Tendency to continue making a formerly correct response when currently incorrect
Piaget's studies of child development - perseveration errors only between 7 and 12 months of development (due to incomplete circuitry in PFC) |
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Term
| Permissive vs instructive experiences? |
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Definition
Permissive - need to happen for info in genetic programs to be manifested
Instructive - those that contribute to direction of development |
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Term
| What chemical was used to find adult neurogenesis? |
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Definition
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Term
| Where does neurogenesis occur in adults? |
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Definition
| Olfactory bulb & hippocampus |
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Term
| Where do new neurons come from in adult neurogenesis? What do they become? |
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Definition
O bulb - from stem cells in SV zone; then migrate; become INTERNEURONS
Hippocampus - from dentate gyrus; become GRANULE CELLS |
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Term
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Definition
| Increased exercise in enriched environments may lead to increased neurogenesis |
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Term
| 3 core symptoms of autism? |
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Definition
Reduced ability to infer emotions of others
Reduced social interaction capacity
Preoccupation with single object/activity (fixation) |
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Term
| ___% of all autism cases are male? |
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Definition
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Term
| What are the most prevalent childhood neurologic disorders? |
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Definition
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Term
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Definition
| Neurodevelopmental disorder associated w/ mental retardation & heterogeneous disability (opposite to autism) |
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Term
| Most noticeable feature of Williams syndrome |
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Definition
| Language abilities; delay in development, but skills are remarkable considering IQ < 60 |
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Term
| Deficits in individuals with Williams syndrome? |
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Definition
Cognitive deficits - spatial abilities are poor compared to others with same IQ
Heart defects - elastin mutation
Reduced cortical volume (inferior frontal cortex)
Elfin appearance |
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Term
| Changes in cortical volume in individuals with Wiliiams syndrome |
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Definition
Decreased - border between parietal & occipital, orbitofrontal (inferior frontal cortex)
Increased - superior temporal gyrus (auditory cortex) |
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Term
| Differences between hypoplasia vs. ectopsia vs. dysplasia? |
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Definition
Hypoplasia - not enough cells; error in cell proliferation
Ectopsia - wrong organization of cells; error in cell migration
Dysplasia - wrong cell morphology; error in cell differentiation |
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Term
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Definition
Ancephaly - not viable
Encephalocele - failure of NT to close rostrally, can survive but w/ deficits
Spina Bifida - failure of NT to close caudally |
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Term
| What are the neuronal abnormalities associated with FASDs? |
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Definition
| Errors in migration; see heterotopias in cortex (ectopsia) |
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Term
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Definition
| Those born w/o corpus callosum |
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Term
| What two deficiencies are almost always assocaited with L hemisphere dysfunction? |
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Definition
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Term
| What are the tests of cerebral lateralization? |
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Definition
Sodium amytal test - anesthetizes ipsilateral hemisphere as side of injection
Dichotic listening test - done w/ digits in each ear; R ear is better
Functional brain imaging |
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Term
| Speech laterality & handedness? |
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Definition
Dextrals - almost always L hemisphere dominant for language
Sinestrals - usually L hemisphere dominant for language, but more variable |
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Term
| Learning in one vs both hemispheres? |
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Definition
| Occurs just as fast (cat experiment) - same learning rate |
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Term
| Gazzaniga protocol in experiment |
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Definition
| Flash words for 0.1 sec to keep them lateralized to visual field/hemisphere correct |
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Term
| Differences in human vs. animal split brain patients? |
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Definition
Animals - hemispheres perform equally
Humans - usually have one dominant hemisphere for a given task |
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Term
| Doing two things at once... |
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Definition
| Put hands in bag to pick out objects seen (pencil from L field, orange from R); when asked, say they have 2 oranges, but when it comes out they have orange in R hand and pencil in L hand |
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Term
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Definition
| When objects in plain site will get conflict between hands as to which object to pick up |
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Term
| What happens to hemisphere involvement as task difficulty increases? |
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Definition
Simple - only need 1
Complex - need both |
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Term
| L hemisphere & ipsilateral movement? |
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Definition
| L hemisphere controls ipsilateral movement more than R; lesion to L hemisphere creates more ipsilateral deficits than lesion to R |
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Term
| R hemisphere & spatial ability? |
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Definition
Hemispheres do task differently (3D object, pick 2D foldout)
R hand (L hemis) - hesitant, talks
L hand (R hemis) - quick, silent |
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Term
| R hemisphere music ability and dichotic listening |
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Definition
R ear (L hemis) - does better with reciting digits
L ear (R hemis) - does better with melodies |
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Term
| L hemisphere is also called the... |
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Definition
| INTERPRETER - tries to assess patterns and look for underlying patterns/rules (behaves like whole brain) |
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Term
| Anatomical asymmetries in the brain? |
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Definition
Frontal operculum - Broca's area
Planum temporale - Wernicke's area (bigger on L)
Heschl's gyrus - primary auditory cortex (bigger on R) |
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Term
| Areas in the Wernicke Geschwind model? |
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Definition
primary motor, visual, auditory cortices
Brocas and Wernickes areas
L angular gyrus
L arcuate fasciculus |
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Term
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Definition
| Caused by damage to arcuate fasciculus -> cannot repeat words they just heard; spontaneous speech is fine |
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Term
| Constituent processes of language are divided into what 3 categories by cognitive neuroscientists: |
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Definition
| Phonological, Grammatical, Semantic |
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Term
| Dyslexia results from a disturbance in __________ |
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Definition
| phonological processing (representation & comprehension of speech sounds) |
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Term
| Two ways reading can be done? |
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Definition
Lexical - for familiar words; remember by word
Phonetic - for unfamiliar words; go letter by letter and sound it out |
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Term
| Surface vs Deep Dyslexia? |
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Definition
Surface - keep phonetic procedure, lose lexical
Deep - keep lexical, lose phonetic; usually due to L hemisphere damage |
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Term
| All meningiomas are _______ tumours? |
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Definition
| ENCAPSULATED (grow in own membrane; cannot metastasize) |
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Term
| Two types of cerebral hemorrage leading to stroke, which is preferred? |
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Definition
| Want subarachnoid as opposed to intracerebral b/c subarachnoid hematoma is easier to remove and less troublesome |
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Term
| What pathologies can lead to hemorrhage in cerebral vasculature? |
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Definition
Aneurysm (to treat either clip or coil embolization)
AVMs (to treat either embolize or radiotherapy/surgery to kill BV tissue) |
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Term
| 3 main causes of ischemia? |
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Definition
Thrombosis (plug formed at site of clot)
Embolism (plug formed elsewhere then migrates to clot site)
Arteriosclerosis (narrowing of artery) |
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Term
| Mechanism of Glu mediated stroke damage in ischemic strokes? |
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Definition
| Massive Glu release from hypoxic neurons; bind to NMDA receptors to cause Na and Ca influx; leads to more Glu release (toxic cascade) |
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Term
| What neurons are more susceptible to ischemic stroke? |
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Definition
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Term
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Definition
| Closed head injury causing cerebrovascular damage; creates hematoma; usually contrecoup injuries (damage opposite to side of the head that was struck) |
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Term
| Bacterial vs. viral infections? |
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Definition
Bacteria = syphilis
Viral = rabies (NS affinity), herpes & mumps |
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Term
| Where is the pathology believed to be in epilepsy? |
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Definition
| At inhibitory GABAergic synapses |
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Term
| Partial vs general epilepsy |
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Definition
Partial - NOT involving the entire brain
General - involves entire brain |
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Term
| Automatisms are seen in... |
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Definition
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Term
| another name for simple partial seizures? |
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Definition
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Term
| What is the EEG diagnostic criteria for petit mal seizures? |
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Definition
| 3 per second spike and wave discharge (bilateral in nature) |
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Term
| Biggest risk factor for AD and PD? |
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Definition
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Term
| Normally DA neurons lost in PD project via ________ to the ______ |
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Definition
via nigrostriatal pathway
to the striatum (caudate + putamen) |
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Term
| All gene mutations for familial PD affect? |
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Definition
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Term
| DBS treatment for PD aimed at? |
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Definition
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Term
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Definition
| CAG (positive > 40 repeats; normal 28-35 repeats) |
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Term
| In HD, abnormal HG protein is present in_________ but__________ affected |
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Definition
present in ALL CELLS
but only NEURONS are affected |
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Term
| Disease progression in HD is due to 2 effects from mutations? |
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Definition
Loss of normal function - increased apoptosis; lower BDNF
Gain of function mutation - increased neuronal inclusions (faster progression with more CAG repeats) |
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Term
| MS is a _________ disorder |
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Definition
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Term
| MS is more prevalent in which gender? |
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Definition
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Term
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Definition
| Vitamin D (higher prevalence in areas further from the equator) |
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Term
| Location of amyloid plaques vs. tangles in AD? |
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Definition
Plaques - extracellular; increased deposition over disease course
Tangles - intracellular; hyperphosphorylation of Tau protein; first seen in hippocampal area CA1 |
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Term
| Areas of peak neuron loss in AD... |
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Definition
Medial temporal structures - entorrhinal cortex, hippocampus, amygdala
Inferior temporal, PFC, posterior parietal - cognition areas |
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Term
| What comes first plaques or cell death? |
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Definition
| Plaque formation PRECEDES cell death |
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Term
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Definition
| Used to stop effects of MPTP in mouse model of PD |
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Term
| Rotenone model - what disease is it used for? |
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Definition
| PD - inject rotenone into neck to mirror PD symptoms (best one b/c of Lewy bodies) |
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